The present invention relates to semiconductor technology, and more particularly to a vertical inductor and method of manufacturing the same.
Due to the continuous demand of increased memory capacity in semiconductor devices, a number of process techniques has been employed to reduce the memory cell structure for increasing the integration density.
As portable electronic devices become more compact, and the number of functions performed by a given device increases, the manufacturing process has become more complex as more functions must be integrated into the given device. Accordingly, 3D integrated circuit technology is being employed more extensively.
Micro-electromechanical systems (MEMS) have the advantages of size, power consumption, weight, reliability and costs. MEMS have been used in a variety of sensors, such as pressure sensors, acceleration sensors, inertial sensors, and other sensors.
In general, integrated passive devices and micro-electromechanical systems (MEMS) contain one or more spiral inductors, which occupy a large silicon area of the integrated circuit. Due to the electric characteristics of inductors, their size cannot be reduced in the same way as feature sizes of devices in the CMOS technology.
FIG. 1A shows a structure of a spiral inductor, which includes a stack of one or more metal layers wound in a polygonal (square) shape in the longitudinal (horizontal) direction. FIG. 1B shows another structure of a spiral inductor, which is formed with two metal layers connected by multiple vias. The structures of FIGS. 1A and 1B are planar and occupy a relative large silicon area.
Furthermore, magnetic fields generated by active areas, polysilicon and metal layers may have an impact on the performance of the spiral inductor so that active areas, polysilicon and metal layers, and dummy patterns are not allowed to be present below the spiral inductor.
Thus, there is a need for a novel spiral inductor structure and a method of manufacturing the same to eliminate the drawbacks of the conventional planar spiral inductors.